Electronics Forum | Tue May 12 04:15:48 EDT 1998 | Chris Sargent
Help! We have been doing some trials on Paste Through Hole and have encountered a problem. The screen is designed (as is suggested in technical info re PTH) to give double the paste volume required to fill the void between the pin and via. The pro
Electronics Forum | Tue Nov 20 12:48:40 EST 2001 | tony_sauve
We recently experienced a problem w/voids (up to 65%) in uBGA solder joints. The only joints that have the problem correlated to pads which had blind 0.006" via's in them. The via's only extend down 2 layers, of the 18. 21 BGA's on the PCB, only expe
Electronics Forum | Wed Jun 03 13:56:09 EDT 2009 | mika
less total area of voids, which mean a much more strength in the joint and much easier to solder such a cooling pad grounded via vias, with this approach! The same goes for big cooling pads of let say Power transistors without any via etc. Always re
Electronics Forum | Wed Mar 25 16:38:21 EST 1998 | Steve Joy
We have successfully put .016" vias in .030" pads. There is no issue with .030" solder balls, since the actual volume of the .002" via in pad is small compared to the ball+solder paste volume. We did notice random bubbles where, apparently, the sol
Electronics Forum | Wed Mar 25 19:41:01 EST 1998 | Earl Moon
| We have successfully put .016" vias in .030" pads. | There is no drain off with .030" solder balls, since | the actual volume in the .002" depression is low. | We did notice random bubbles where, apparently, the | solder reflowed and trapped the a
Electronics Forum | Tue Jul 06 19:38:01 EDT 1999 | John
Q #1) Is it more reliable to have the mask tent over the vias or risk getting vias half filled with solder? These are vias with an .020" hole and .040" or .050" pad. Q #2) When speaking of annular rings, I have always thought of them as minimums. Su
Electronics Forum | Wed Feb 05 21:05:38 EST 2003 | davef
Iman On your situation: As an earlier poster stated, your options are limited to opening you stencil aperture to compensate for the paste lost to the via. On your designer's belief that "it helps in heat dissipation": Could be true, but: * Hole wil
Electronics Forum | Thu Oct 01 08:34:50 EDT 2009 | davef
First, the reflow thermal recipe provided by your paste supplier is only a ball park guess. Beyond that, the temperature measured by thermocouples on your oven heaters are only loosely related the temperature of solder paste on your board. You need t
Electronics Forum | Mon Jul 26 12:55:34 EDT 1999 | M.L
Presently protos of micro-bgas (80i/o) pitch .030/.031 12BGA per assembly The board is a (.062, 4 layers) FR-4 using Dry film Pads .014inch Vias within footprint .020inch Vias to be filled by bottom side(solder side) only .030in dia. Force via plugg
Electronics Forum | Wed Mar 14 13:52:11 EDT 2007 | Oswaldo Rey
Vias are thru hole, pcb is two sided, bottom copper is 2 sq inches, vias are 0.6mm diameter. thanks,
